Noisy rear diff (D44A) after oil seal replacement

[Reiver]

My rear diff (D44A) oil seal let go so I replaced it following all the advice re marking nut, yoke & diff housing.

The yoke was worn where it had been riding on the seal so I decided a new (Spicer) yoke was in order. I marked it up as per the original & slotted it in.

I also fitted a new nut which may have been a mistake. I marked it up like the original and wound it on. My torque wrench only goes up to 150 ft/lbs so I set it to 100 initially figuring that would give me plenty of warning when I started to approach the 220 ft/lbs recommended on various forums. I never got the torque wrench to clack but I was halfway round past the mark. My socket wouldn't seat fully down on to the nut as the new yoke stopped it so I was wary of rounding the nut off.

A run up the road seemed fine until I lifted off. On the the overrun there's a loud graunching which disappears when I get back on the throttle.

Have I not got the pinion nut tight enough? There's no in/out movement on the yoke. I can't believe I've got it too tight.

[Reiver]

I've ordered a non-impact 1 5/16 socket which will hopefully fit onto the nut better.

I'm wondering if I should refit the old nut - that might reduce the variables.

I've also seen one forum thread quote a re-torque figure of 160 ft/lbs - that's more achievable than 220. I'm not as young as I was !

[Classic Boy]

In my experience if it is noisy on overrun it is likely a pinion bearing failure. The marking of parts method of seal replacement is only reliable when original parts are reinstalled..
The bearing may have been on its way out before you started and now due to the torque issue you describe has exposed the problem.

[JoergM]

Originally Posted by Reiver

My rear diff (D44A) oil seal let go so I replaced it following all the advice re marking nut, yoke & diff housing.

The yoke was worn where it had been riding on the seal so I decided a new (Spicer) yoke was in order. I marked it up as per the original & slotted it in.

I also fitted a new nut which may have been a mistake. I marked it up like the original and wound it on. My torque wrench only goes up to 150 ft/lbs so I set it to 100 initially figuring that would give me plenty of warning when I started to approach the 220 ft/lbs recommended on various forums. I never got the torque wrench to clack but I was halfway round past the mark. My socket wouldn't seat fully down on to the nut as the new yoke stopped it so I was wary of rounding the nut off.

A run up the road seemed fine until I lifted off. On the the overrun there's a loud graunching which disappears when I get back on the throttle.

Have I not got the pinion nut tight enough? There's no in/out movement on the yoke. I can't believe I've got it too tight.

220 ft/lbs sounds way too much. You did not mention that you have installed a new crush sleeve, have you? the 220 ft/lbs are only required for a new crush sleeve to actually crush and sit since the Dana 44a does not have shims. And that's only the force taken to crush it since it will still sit pretty loose. The pre-load (turning force of the pinion without the carrier installed) of a new bearing is only 24 inch/lbs as far as I recall. For a used one it is even lower. So my guess is, that your nut is way too tight and that the bearing is eating itself if you do not take care of it. I have made same mistakes when I took mine apart and had to learn it the hard way.

[Reiver]

I didn't install a new crush washer and didn't get the torque up to 220 ft/ilbs.

In fact I don't think I even got the torque up to 100 as the wrench didn't 'clack'.
That's because I couldn't get the impact socket to sit fully on the nut.

I've since found a thread which says torque up to 160 and check the rotating torque which should be 10 - 15 ins/lbs.

I should then increase the pinion torque in 5 ft/lb increments until the rotating torque hits 10 - 15 ins/lbs. This sounds like a plan (once I get the new socket).

Nothing ventured !

[JoergM]

Originally Posted by Reiver

I didn't install a new crush washer and didn't get the torque up to 220 ft/ilbs.

In fact I don't think I even got the torque up to 100 as the wrench didn't 'clack'.
That's because I couldn't get the impact socket to sit fully on the nut.

I've since found a thread which says torque up to 160 and check the rotating torque which should be 10 - 15 ins/lbs.

I should then increase the pinion torque in 5 ft/lb increments until the rotating torque hits 10 - 15 ins/lbs. This sounds like a plan (once I get the new socket).

Nothing ventured !

I had my Dana44A apart as well. I took the axle shafts and the diff carrier out and changed the bearing of my pinion (I had some old spider gear parts in which ate up the crush sleeve as well as the bearing races). I tried to install a new crush sleeve but I did not have any space underneath the car to actually crush it, so I simply reused the installed one. I did not care about the torque of the pinion nut itself but only the pre-load of the pinion and then the backlash of the carrier to be sure. I used an impact gun to tighten up the nut till i had the pre-load right. I made sure that I install the pinion nut with red thread lock so it wont come loose again, esp. since you might not need to torque it up to 100 ft/lbs.

That's how I did it and how I would do it again if I would be in the same position. This was 2 1/2 years ago and I was driving with this thing from Melbourne to Queensland without any issue.

But you are right with the socket. I had to get an impact socket with rather thing sidewalls. The standard did not fit since the space was too tight.

[JoergM]

i did same thing in the front on my Dana 30. This was when I got my WJ and I had no idea what to do. The nut came loose and the pinion was wallowing around and under stress it jumped gears.
I then tighten the nut up (not much) but even this little bit was too tight and I had same issue as you described. As soon as I was driving a bit faster than 60 or 70km/h I had this buzzing noise . After loosening the nut, the noise disappeared.